Short answer
Prioritize increasing the share of virgin polypropylene in the outer layers of thermoformed cups when incorporating recyclates in the core to maintain or improve top load strength and manage shrinkage.
- Field
- Final Production
- Source
- Journal of Applied Polymer Science (2023)
- Method
- Experimental
- Evidence
- Strong effect
Adjusting the proportion of virgin material in the outer layers of thermoformed cups can significantly improve the mechanical properties and reduce shrinkage when using post-consumer polypropylene recyclates in the core. This final production research insight is drawn from a 2023 study published in Journal of Applied Polymer Science. Using Experimental, researchers explored how this design variable affects real-world outcomes. The key design takeaway: Prioritize increasing the share of virgin polypropylene in the outer layers of thermoformed cups when incorporating recyclates in the core to maintain or improve top load strength and manage shrinkage.
Increasing top layer share enhances recyclate cup performance in thermoforming
Adjusting the proportion of virgin material in the outer layers of thermoformed cups can significantly improve the mechanical properties and reduce shrinkage when using post-consumer polypropylene recyclates in the core.
Journal of Applied Polymer Science · 2023
Key Findings
- 01Post-consumer polypropylene recyclates exhibit lower stiffness but higher toughness due to polyethylene contamination.
- 02Thermoformed cups with recyclate core layers show reduced shrinkage compared to virgin material cups.
- 03Most cups with recycled content had lower top load strength than the control.
- 04Increasing the top layer share, blending recyclate with virgin material, or increasing overall film thickness all improved shrinkage and top load.
- 05Increasing overall film thickness was found to be economically unfeasible.
Application
Design takeaway
Prioritize increasing the share of virgin polypropylene in the outer layers of thermoformed cups when incorporating recyclates in the core to maintain or improve top load strength and manage shrinkage.
How to apply
When designing thermoformed products with recycled content, consider a multilayer approach where the recyclate forms the core and virgin material constitutes a significant portion of the outer layers. Experiment with different ratios of virgin to recycled material in the layers to find an optimal balance between cost, performance, and sustainability.
Project actions
- 01When researching materials for your design project, consider how different types of recycled plastics behave in manufacturing processes.
- 02Investigate the potential for using multilayer structures to combine the benefits of virgin and recycled materials.
Method & Evidence
Variables
Strengths & Limitations
Strengths
- +Investigated practical strategies for improving recyclate use.
- +Tested both material and product level performance.
- +Provided clear design implications for multilayer structures.
Limitations
The specific types of recycled polypropylene used might not represent all available recyclates. The study focused on cups, so results might differ for other thermoformed shapes.
Reliability & validity
The study's validity is supported by testing at both material and product levels and by comparing multiple improvement strategies against a control. Reliability would be enhanced by reporting statistical significance of findings and potential variations in material batches.
Think critically
While increasing the top layer share is effective, what are the economic implications of using a higher percentage of virgin material, and how can this be balanced with the environmental goals of using recyclates?
Design Principles
"Multilayer material construction allows for the optimization of product performance by strategically combining different material properties, such as using virgin materials for surface integrity and recyclates for bulk volume."
This research offers practical strategies for designers and manufacturers looking to incorporate recycled plastics into high-volume products like cups. By understanding how to balance recyclate content with virgin material distribution, companies can achieve better product performance and meet sustainability goals without compromising quality.
What This Means for Your Design
If you want to make cups from recycled plastic, using more of the new plastic on the outside and the recycled plastic on the inside helps make the cups stronger and less likely to shrink.
How to use in your project
- 1.Reference this study when discussing material selection for your design project, particularly if you are considering the use of recycled plastics.
- 2.Use the findings to justify design choices related to material composition and manufacturing processes.
Add to My Project
Quick Cite
Paragraph starter
The research by Traxler et al. (2023) demonstrates that incorporating post-consumer polypropylene recyclates into the core layer of thermoformed cups can lead to reduced shrinkage but potentially lower top load strength. However, strategic adjustments, such as increasing the proportion of virgin polypropylene in the outer layers, can effectively enhance product performance, making the use of recyclates a viable option for sustainable design in packaging.
Source
Journal of Applied Polymer Science
Strategies for improving product properties of thermoformed multilayer cups with contents of post‐consumer polypropylene recyclates
journal · 2023
View sourceQuestions About This Research
- What does the research say about increasing top layer share enhances recyclate cup performance in thermoforming?
- Prioritize increasing the share of virgin polypropylene in the outer layers of thermoformed cups when incorporating recyclates in the core to maintain or improve top load strength and manage shrinkage. Evidence: Journal of Applied Polymer Science (2023).
- Why does "Increasing top layer share enhances recyclate cup performance in thermoforming" matter for design?
- This research offers practical strategies for designers and manufacturers looking to incorporate recycled plastics into high-volume products like cups. By understanding how to balance recyclate content with virgin material distribution, companies can achieve better product performance and meet sustainability goals without compromising quality.
- How can designers apply this research?
- Prioritize increasing the share of virgin polypropylene in the outer layers of thermoformed cups when incorporating recyclates in the core to maintain or improve top load strength and manage shrinkage.
- What were the main findings?
- Post-consumer polypropylene recyclates exhibit lower stiffness but higher toughness due to polyethylene contamination.. Thermoformed cups with recyclate core layers show reduced shrinkage compared to virgin material cups.. Most cups with recycled content had lower top load strength than the control.. Increasing the top layer share, blending recyclate with virgin material, or increasing overall film thickness all improved shrinkage and top load.
- What research method was used?
- Experimental.
- How strong is the evidence?
- Evidence strength is rated Strong effect, based on a 2023 journal from Journal of Applied Polymer Science.
- What should I do differently in my next project?
- When designing thermoformed products with recycled content, consider a multilayer approach where the recyclate forms the core and virgin material constitutes a significant portion of the outer layers. Experiment with different ratios of virgin to recycled material in the layers to find an optimal balance between cost, performance, and sustainability.
- What are the limitations?
- The study focused on specific commercially available recyclates and a particular multilayer structure; results may vary with different recyclate compositions or processing parameters. Economic feasibility of increasing overall film thickness was not fully explored beyond initial assessment.